1. Field of the present invention
The present invention is in the field of communications; and in particular it relates to the transmission of broadband communication data over a three-line electrical mains supply.
2. Description of the Related Art
Communication systems are well known and include Local Area Networks (LANs), Wide Area Networks (WANs), cellular networks, Wireless Local Area Networks (WLANs), Wireless Wide Area Networks (WWANs), Personal Area Networks (PANs), etc. With the growing need for the exchange of digital content (e.g. MP3 audio, MPEG4 video and digital photographs) there is a widely recognized need to improve digital communication systems. Powerline communication (PLC) is a technology that encodes data in a signal and transmits the signal on existing electricity powerlines in a band of frequencies that are not used for supplying electricity. Accordingly, PLC leverages the ubiquity of existing electricity networks to provide extensive network coverage. Furthermore, since PLC enables data to be accessed from conventional power-outlets, no new wiring needs to be installed in a building (or different parts of a building). Accordingly, PLC offers the additional advantage of reduced installation costs.
In some buildings or installations, PLC communications may be the best option for servicing communications, e.g., wireless communications incapable of penetrating walls or other structure, wireless communications deemed too insecure, installing wiring for other communication types is too expensive, etc. However, in other structures, WLANs, for example may be easier to install and service. For example, many coffee shops, restaurants, hotels, and other retail establishments use WLANs to service their customers. In still other installations, cable modem, Local Area Network (LAN), and/or other communication networks may be employed to service communications.
Each communication device includes transmit path components and receive path components, both of which couple to a servicing media, antenna, or other transmission path element. In the receive path, a received signal must be amplified prior to processing to extract data. Some received signals have a very large dynamic range, which must be effectively serviced to successfully extract incoming data. An amplifying receiver with a large dynamic range has different requirements for different level of input signal strength. Large signals (up to 10V or more) put stringent linearity requirements on the input amplifier. Small input signals (1 mV or less) require a very low noise amplifier. These two requirements are very difficult to meet with a single amplifier without select ability directed by input-signal strength.